Hey, not sure if there’s any place to rent. To buy, only a hitch would fit a 4 bike rack. Not sure if you want that for a one time use. They are usually pretty expensive.
For a 2 bike or 3 bike rack on your trunk, you can’t go wrong with Saris Bones.
There are cheap bike racks by Allen Sports, but check the online review before you buy. They would work, but the quality may be lacking and long term durability questionable.